JP3558095B2

JP3558095B2 - Stereolithography

Info

Publication number: JP3558095B2
Application number: JP32047894A
Authority: JP
Inventors: 弘之楢原; 悟五十嵐; 勝政斎藤
Original assignee: JSR Corp
Current assignee: JSR Corp
Priority date: 1994-12-22
Filing date: 1994-12-22
Publication date: 2004-08-25
Anticipated expiration: 2019-08-25
Also published as: JPH08174680A

Description

【０００１】
【産業上の利用分野】
本発明は、感光性樹脂液を用いた積層法による三次元形状を有する積層体の造形方法に関するものである。
【０００２】
【従来の技術】
感光性樹脂を用いて三次元形状を造形する方法としては、造形しようとする形状をコンピュータなどを用いて等高断面輪郭データとし、これに従って紫外線レーザーを感光性樹脂に選択的に照射して重合硬化させ、積層により造形する光造形方法が知られている。
【０００３】
【発明が解決しようとする課題】
ところで産業界における光造形方法の主な利用分野は、意匠模型等の製造である。これらの分野では、成形体の曲面の質が問題とされ、模型表面の滑らかさが期待される。しかしながら上記のような造形方法では、三次元形状を複数の薄い層に分割するため、模型表面に段差が発生し、表面の滑らかさが損なわれる。特に、模型表面の傾斜角が小さくなると表面粗さが大きくなる。
【０００４】
また、光造形方法により造形された造形模型を元型として型をとり、異なった素材のものに形状を転写しようすると、この段差がそのまま転写されてしまう。さらに、型取りなどの段階で、段差が引っ掛かり型がうまく作れないなどの問題もあった。
【０００５】
これらの問題を解決する方法としては、層厚さを薄くして段差を減少させる方法がある。しかしながら、層厚さを薄くして層の数をたとえばｎ倍にすると、表面粗さは約１／ｎとなるが、同時に造形時間がｎ倍となる。
【０００６】
このため従来では、光造形方法により得られた積層体表面の段差を２次加工によりなくし、表面を滑らかにしていた。
【０００７】
【課題を解決するための手段】
本発明は上記のように、各硬化層間の段差が小さく、表面粗さの小さな積層体を造形することができるような光造形方法を提供することを目的とするものであって、感光性樹脂液の表面に光を照射して硬化層を形成し、この硬化層を複数積層して所望の三次元形状を有する積層体を造形する光造形方法において、
（Ａ−１）感光性樹脂に光を照射してＮ層目の硬化層を形成する工程、
（Ｂ−１）このＮ層目の硬化層が感光性樹脂液面の上に出るように積層体を引き上げることにより、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液を滞留させる工程、
（Ｃ−１）Ｎ層目の硬化層が感光性樹脂液面上に出た状態で前記段差部分に滞留した感光性樹脂液を硬化させる工程、
（Ｄ−１）積層体を（Ｎ＋１）層目を形成する位置まで引下げる工程
を含む光造形方法である。
【０００８】
上記目的は、感光性樹脂液の表面に光を照射して硬化層を形成し、この硬化層を複数積層して所望の三次元形状を有する積層体を造形する光造形方法において、
（Ａ−２）感光性樹脂に光を照射してＮ層目の硬化層を形成する工程、
（Ｂ−２）このＮ層目の硬化層を感光性樹脂液面の上に出るように積層体を引き上げることにより、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液を滞留させる工程、
（Ｃ−２）Ｎ層目の硬化層が感光性樹脂液面上に出た状態で前記段差部分に滞留した感光性樹脂液のみに光を照射して、感光性樹脂を硬化させる工程、
（Ｄ−２）積層体を（Ｎ＋１）層目を形成する位置まで引下げる工程
を含む光造形方法によっても達成することができる。
【０００９】
また上記目的は、感光性樹脂液の表面に光を照射して硬化層を形成し、この硬化層を複数積層して所望の三次元形状を有する積層体を造形する光造形方法において、
（Ａ−３）感光性樹脂に光を照射してＮ層目の硬化層の少なくとも一部を形成する工程、
（Ｂ−３）このＮ層目の硬化層を感光性樹脂液面の上に出るように積層体を引き上げることにより、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液を滞留させる工程、
（Ｃ−３）Ｎ層目の硬化層が感光性樹脂液面上に出た状態で（Ｎ−１）層目の硬化層の形状に従って光を照射して、前記段差部分に滞留した感光性樹脂を硬化させるとともにＮ層目の未硬化の感光性樹脂を硬化させる工程、
（Ｄ−３）積層体を（Ｎ＋１）層目を形成する位置まで引下げる工程
を含む光造形方法によっても達成することができる。
【００１０】
【作用】
本発明の光造形方法は、Ｎ層目の硬化層を形成した後、Ｎ層目の硬化層を感光性樹脂液面上に引上げ、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂を滞留させ、この状態で前記段差部分に滞留した感光性樹脂を硬化させているので、各硬化層間の段差がほとんどなく、表面が滑らかな積層体を造形することができる。
【００１１】
【発明の具体的説明】
以下、本発明に係る光造形方法について図面を参照しつつ具体的に説明する。図１は、本発明に係る光造形方法の製造工程を模式的に示す図である。図２は、製造例で製造した評価模型の概略斜視図である。図２中２１は１０度の傾斜を有する面であり、２２は２０度の傾斜を有する面であり、２３は３０度の傾斜を有する面であり、２４は４０度の傾斜を有する面であり、２５は５０度の傾斜を有する面であり、２６は６０度の傾斜を有する面であり、２７は７０度の傾斜を有する面であり、２８は８０度の傾斜を有する面であり、２９は９０度の傾斜を有する面である。
【００１２】
本発明に係る光造形方法は、まず感光性樹脂１に光５を照射してＮ層目の硬化層７を形成する工程（以下「工程（Ａ−１）」という）を行う。エレベータ２を引き下げることにより、積層体１０上（またはベースプレート３上）に１層分の厚さの感光性樹脂１を回り込ませ、光５でＮ層目を描画し、感光性樹脂を硬化させＮ層目の硬化層７を形成するとともに、Ｎ層目の硬化層７と（Ｎ−１）層目の硬化層８とを接合させる。すなわち、図１（ａ）に示すように、ベースプレート３上に１層の厚さの感光性樹脂１を回り込ませ、光５でＮ層を描画し、感光性樹脂１を硬化させる。
【００１３】
なお、本発明では感光性樹脂として従来公知の感光性樹脂をすべて用いることができる。また、感光性樹脂を硬化させるための光は、用いる感光性樹脂にもよるが赤外線、可視光線、紫外線、紫外線レーザーなどが用いられる。
【００１４】
次に、このＮ層目の硬化層７が感光性樹脂液面の上に出るように積層体１０を引き上げることにより、Ｎ層目の硬化層７と（Ｎ−１）層目の硬化層８との段差部分に感光性樹脂液を滞留させる工程（以下「工程（Ｂ−１）」という）を行う。続いて、Ｎ層目の硬化層７が感光性樹脂液面上に出た状態で前記段差部分に滞留した感光性樹脂液４を硬化させる工程（以下「工程（Ｃ−１）」という）を行う。すなわち、例えば図１（ｂ）に示すように、ベースプレート３を上昇させて、前記Ｎ層目の硬化層に（Ｎ−１）層目の硬化層８の形状に従って光５を照射する。
【００１５】
Ｎ層目の硬化層７が感光性樹脂液面の上に出るように積層体１０を引き上げると、Ｎ層目の硬化層７の周縁部と（Ｎ−１）層目の硬化層８との段差部分に感光性樹脂液が滞留し、段差を埋めて斜面を形成する。この段差部分に滞留した滞留感光性樹脂液４を硬化させると、段差がほとんどない積層体が得られる。
【００１６】
積層体１０を引き上げる幅は、図１（ｂ）では硬化層の厚さであるが、本発明では積層体１０を引き上げる幅は、硬化層の厚さ以上であれば特に制限されない。積層体１０を引き上げる幅が硬化層の厚さの２層分以上であると、不要な感光性樹脂が流れ落ちるため好ましい。
【００１７】
次に、積層体１０を（Ｎ＋１）層目を形成する位置まで引下げる工程（以下「工程（Ｄ−１）」という）を行う。積層体１０を（Ｎ＋１）層を形成する位置まで引き下げることにより、Ｎ層目の積層体７の上に１層分の厚さの感光性樹脂１を回り込ませる。すなわち、図１（ｃ）に示すように、ベースプレート３を次の（Ｎ＋１）層を形成する深さまで沈下させる。
【００１８】
続いて図１（ｄ）に示すように、（Ｎ＋１）層を描画して感光性樹脂を硬化させるとともに、下部の硬化層と接合させる。
積層体１０を（Ｎ＋１）層目を形成する位置まで引下げる際には、一旦積層体１０を（Ｎ＋１）層目を形成する位置より下方に引下げ、その後積層体１０を（Ｎ＋１）層目を形成する位置まで引き上げてもよい。
【００１９】
光５で（Ｎ＋１）層目を描画すると、感光性樹脂１が硬化し（Ｎ＋１）層目の硬化層９を形成するとともに、Ｎ層目の硬化層７と（Ｎ＋１）層目の硬化層９とが接合する。
【００２０】
前記工程（Ａ−１）、工程（Ｂ−１）、工程（Ｃ−１）および工程（Ｄ−１）を形状の最終層まで繰り返すことにより立体模型を造形することができる。
なお、光を照射する際には、滞留した感光性樹脂液が動かないようにすることが望ましい。
【００２１】
本発明の光造形方法は、Ｎ層目の硬化層を形成した後、このＮ層目の硬化層を上昇させ、Ｎ層目の硬化層の周縁部に未硬化の感光性樹脂が滞留させて、この未硬化の感光性樹脂を硬化させているので段差がほとんどない積層体を造形することができる。
【００２２】
以上、本発明に係る光造形方法について説明したが本発明は上記例に限定されず、本発明の技術的思想の範囲内で種々変形可能である。
たとえば、以下のように行うこともできる。
【００２３】
まず、前記工程（Ａ−１）と同様にしてＮ層目の硬化層を形成する工程（以下「工程（Ａ−２）」という）を行う。
次に、前記工程（Ｂ−１）と同様に、このＮ層目の硬化層が感光性樹脂液面の上に出るように積層体を引き上げることにより、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液を滞留させる工程（以下「工程（Ｂ−２）」という）を行う。
【００２４】
続いて、Ｎ層目の硬化層が感光性樹脂液面上に出た状態で、段差に滞留した感光性樹脂にのみ光を照射して、前記段差部分に滞留した感光性樹脂液を硬化させる工程（以下「工程（Ｃ−２）」という）を行う。
【００２５】
次に、前記工程（Ｄ−１）と同様に、積層体を（Ｎ＋１）層目を形成する位置まで引下げる工程（以下「工程（Ｄ−２）」という）を行う。
前記工程（Ａ−２）、工程（Ｂ−２）、工程（Ｃ−２）および工程（Ｄ−２）を形状の最終層まで繰り返すことにより立体模型を造形することができる。
【００２６】
このような方法によっても、Ｎ層目の硬化層を形成した後、このＮ層目の硬化層を上昇させ、Ｎ層目の硬化層の周縁部に未硬化の感光性樹脂が滞留させて、この未硬化の感光性樹脂を硬化させているので前記と同様の作用効果を奏することができる。
【００２７】
本発明の光造形方法は、さらに変形可能であり、たとえば、以下のように行うこともできる。
まず、感光性樹脂に光を照射してＮ層目の少なくとも一部を形成する工程（以下「工程（Ａ−３）」という）を行う。エレベータを引き下げることにより、積層体上（またはベースプレート上）に１層分の厚さの感光性樹脂を回り込ませ、光でＮ層目の少なくとも一部を描画し、感光性樹脂を硬化させＮ層目の少なくとも一部を形成する。ここではＮ層目の周縁部のみを硬化させるか、Ｎ層目の光照射パターンの全面を複数の連続もしくは不連続な線状に硬化させるか、あるいはＮ層目の光照射パターンの全面を任意の間隔を有する複数の点状に硬化させる。
【００２８】
次に、前記工程（Ｂ−１）と同様に、このＮ層目の硬化層が感光性樹脂液面の上に出るように積層体を引き上げることにより、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液を滞留させる工程（以下「工程（Ｂ−３）」という）を行う。Ｎ層目の硬化層が感光性樹脂液面の上に出るように積層体を引き上げると、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液が滞留し、段差を埋めて斜面を形成する。
【００２９】
続いて、Ｎ層目の硬化層が感光性樹脂液面上に出た状態で、（Ｎ−１）層目の硬化層の形状に従って光を照射して、前記段差部分に滞留した感光性樹脂を硬化させるとともにＮ層目の未硬化の感光性樹脂を硬化させる工程（以下「工程（Ｃ−３）」という）を行う。Ｎ層目の硬化層が感光性樹脂液面上に出た状態で、（Ｎ−１）層目の硬化層の形状に沿って光を照射すると、段差部分に滞留した感光性樹脂が硬化し段差の少ない積層体を形成するとともに、Ｎ層目の未硬化の感光性樹脂が硬化してＮ層目の硬化層を形成する。
【００３０】
次に、前記工程（Ｄ−２）と同様に、積層体を（Ｎ＋１）層目を形成する位置まで引下げる工程（以下「工程（Ｄ−３）」という）を行う。
前記工程（Ａ−３）、工程（Ｂ−３）、工程（Ｃ−３）および工程（Ｄ−３）を形状の最終層まで繰り返すことにより立体模型を造形することができる。
【００３１】
このような方法によっても、Ｎ層目の硬化層を形成した後、このＮ層目の硬化層を上昇させ、Ｎ層目の硬化層の周縁部に未硬化の感光性樹脂が滞留させて、この未硬化の感光性樹脂を硬化させているので前記と同様の作用効果を奏することができる。
【００３２】
【実施例】
以下、実施例に基づいて本発明をさらに具体的に説明するが、本発明はこれら実施例に限定されるものではない。
【００３３】
【実施例１】
上述した本発明の方法に従って下記条件で、図２に示すような水平面に対し１０〜９０度の範囲の１０度おきの傾斜面を有する評価模型を造形した。
【００３４】
すなわち、感光性樹脂液（日本合成ゴム（株）製、ＳＣＲ２００）の表面に紫外線レーザー光を照射してＮ層目の硬化層を形成した後、このＮ層目の硬化層が感光性樹脂液面の上に出るようにエレベータで積層体を引き上げること（本発明における工程（Ｂ−１）、（Ｂ−２）、（Ｂ−３）に相当し、表１中、本発明における引き上げ条件に該当する）により、Ｎ層目の硬化層と（Ｎ−１）層目の硬化層との段差部分に感光性樹脂液を滞留させた。一定時間保持（表１中、引き上げ量静置時間）後、（Ｎ−１）層目の硬化層の形状に従って紫外線レーザー光を照射して、前記段差部分に滞留した感光性樹脂液を硬化させた。次に、エレベータで積層体を下げ、一定時間保持し感光性樹脂をＮ層目の硬化層の上面に回り込ませた後、積層体を（Ｎ＋１）層目を形成する位置まで引上げ一定時間保持し、紫外線レーザー光を照射して（Ｎ＋１）層目の硬化層を形成した。以上の工程を繰り返すことにより評価模型を造形した。造形後、評価模型に水銀灯を照射し、２時間ポストキュア処理を行った。
【００３５】
【表１】

【００３６】
上記のようにして造形した評価模型の各傾斜面の平均表面粗さを表面粗さ計（ミツトヨ（株）製、サーフコム３００Ｂ）を用いて測定した。
【００３７】
【比較例１】
従来の方法に従って下記条件で、図２に示すような評価模型を造形した。
すなわち、感光性樹脂液（日本合成ゴム（株）製、ＳＣＲ２００）の表面に紫外線レーザー光を照射してＮ層目の硬化層を形成した。次に、エレベータで積層体を下げ、一定時間保持して感光性樹脂をＮ層目の硬化層の上面に回り込ませた後、積層体を（Ｎ＋１）層目を形成する位置まで引上げ一定時間保持し、紫外線レーザー光を照射して（Ｎ＋１）層目の硬化層を形成した。以上の工程を繰り返すことにより評価模型を造形した。
【００３８】
【表２】

【００３９】
上記のようにして造形した評価模型の各傾斜面の平均表面粗さを実施例１と同様にして測定した。
【００４０】
以上の結果を結果を図３に示す。図３に示すように、本発明の方法によると従来の方法に比べて表面粗さは小さくなり、平均表面粗さが１５μｍ以下となっている。
【００４１】
【実施例２】
積層厚みを３００μｍとした以外は、実施例１と同様にして評価模型を造形した。得られた評価模型の各傾斜面の平均表面粗さを実施例１と同様にして測定した。
【００４２】
【比較例２】
積層厚みを３００μｍとした以外は、比較例１と同様にして評価模型を造形した。得られた評価模型の各傾斜面の平均表面粗さを実施例１と同様にして測定した。
【００４３】
以上の結果を図４に示す。また、図５に実施例２で造形した評価模型の傾斜面（破線）と、比較例２で成形した評価模型の傾斜面（実線）の断面曲線を示す。図４に示すように、本発明の方法によると従来の方法に比べて表面粗さは小さくなり、特に３０度以下の傾斜面ではすべての場合平均表面粗さが１５μｍ以下となっている。また、図５に示すように本発明の方法によると、特に傾斜角が小さい場合、段差が小さく、表面粗さが小さくなっている。
【００４４】
【発明の効果】
本発明の光造形方法によると、従来の光造形方法に比べて表面粗さの小さな積層体を造形することができ、積層厚みを大きくしても表面粗さの小さな積層体を造形することができる。このため、積層体の段差を取り除くなどの２次加工をする必要がなく、所望する形状の模型などを、低コスト、短時間で得ることができる。
【図面の簡単な説明】
【図１】本発明に係る光造形方法の製造工程を模式的に示す図である。
【図２】実施例で製造した評価模型の概略斜視図である。
【図３】実施例１で造形した評価模型および比較例１で造形した評価模型の斜面の表面粗さを示した図である。
【図４】実施例２で造形した評価模型および比較例２で造形した評価模型の斜面の表面粗さを示した図である。
【図５】実施例２で造形した評価模型および比較例２で造形した評価模型の断面曲線の比較図である。図中破線は実施例２で造形した評価模型の断面曲線であり、実線は比較例２で造形した評価模型の断面曲線である。
【符号の説明】
１０ … 積層体
１ … 感光性樹脂液
２ … エレベータ
３ … ベースプレート
４ … 滞留感光性樹脂液
５ … 光[0001]
[Industrial applications]
The present invention relates to a method for forming a three-dimensionally shaped laminate by a lamination method using a photosensitive resin liquid.
[0002]
[Prior art]
As a method of forming a three-dimensional shape using a photosensitive resin, the shape to be formed is converted into contour contour data using a computer or the like, and the photosensitive resin is selectively irradiated with an ultraviolet laser according to the data to perform polymerization. 2. Description of the Related Art An optical molding method for curing and forming by lamination is known.
[0003]
[Problems to be solved by the invention]
By the way, the main field of use of the stereolithography method in the industry is the manufacture of design models and the like. In these fields, the quality of the curved surface of the molded article is a problem, and smoothness of the model surface is expected. However, in the modeling method as described above, since the three-dimensional shape is divided into a plurality of thin layers, a step is generated on the model surface, and the smoothness of the surface is impaired. In particular, as the inclination angle of the model surface decreases, the surface roughness increases.
[0004]
In addition, if a mold is formed using a modeling model formed by the optical molding method as a master and the shape is to be transferred to a different material, the step is transferred as it is. In addition, there was a problem that a step was caught at the stage of molding and the mold could not be formed properly.
[0005]
As a method of solving these problems, there is a method of reducing the step by reducing the layer thickness. However, when the layer thickness is reduced and the number of layers is increased, for example, by n times, the surface roughness is reduced to about 1 / n, but at the same time, the modeling time is increased by n times.
[0006]
For this reason, conventionally, the step on the surface of the laminate obtained by the optical shaping method has been eliminated by secondary processing, and the surface has been smoothed.
[0007]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION As described above, an object of the present invention is to provide a stereolithography method capable of forming a laminate having a small step between respective cured layers and having a small surface roughness, and a photosensitive resin. In a light molding method of irradiating light on the surface of the liquid to form a cured layer, and laminating a plurality of the cured layers to form a laminate having a desired three-dimensional shape,
(A-1) a step of irradiating the photosensitive resin with light to form an N-th cured layer;
(B-1) By pulling up the laminate so that the N-th cured layer is above the photosensitive resin liquid surface, the N-th cured layer and the (N-1) -th cured layer are separated. A step of retaining the photosensitive resin liquid at the step portion,
(C-1) a step of curing the photosensitive resin liquid staying at the step portion in a state where the N-th cured layer is on the photosensitive resin liquid surface;
(D-1) An optical shaping method including a step of lowering the laminate to a position where the (N + 1) th layer is formed.
[0008]
The above object is to form a cured layer by irradiating the surface of the photosensitive resin liquid with light, and to form a laminate having a desired three-dimensional shape by laminating a plurality of the cured layers,
(A-2) a step of irradiating the photosensitive resin with light to form an N-th cured layer;
(B-2) By pulling up the laminate so that the N-th cured layer is exposed above the surface of the photosensitive resin, the N-th cured layer and the (N-1) -th cured layer are separated. A step of retaining the photosensitive resin liquid at the step portion,
(C-2) a step of irradiating only the photosensitive resin liquid staying at the step portion with the N-th cured layer on the photosensitive resin liquid surface to cure the photosensitive resin,
(D-2) It can also be achieved by a stereolithography method including a step of pulling down the laminate to a position where the (N + 1) th layer is formed.
[0009]
Further, the above object is to form a cured layer by irradiating light to the surface of the photosensitive resin liquid, and in a stereolithography method of forming a laminate having a desired three-dimensional shape by laminating a plurality of the cured layers,
(A-3) a step of irradiating the photosensitive resin with light to form at least a part of an N-th cured layer;
(B-3) By pulling up the laminate so that the N-th cured layer is exposed above the surface of the photosensitive resin, the N-th cured layer and the (N-1) -th cured layer are separated. A step of retaining the photosensitive resin liquid at the step portion,
(C-3) With the N-th cured layer exposed above the photosensitive resin liquid surface, light is irradiated according to the shape of the (N-1) -th cured layer, and the photo-sensitivity remaining at the step portion is irradiated. Curing the N-th layer uncured photosensitive resin while curing the resin,
(D-3) It can also be achieved by a stereolithography method including a step of pulling down the laminate to a position where the (N + 1) th layer is formed.
[0010]
[Action]
In the stereolithography method of the present invention, after forming the N-th cured layer, the N-th cured layer is pulled up on the surface of the photosensitive resin liquid, and the N-th cured layer and the (N-1) -th layer are cured. Since the photosensitive resin is retained in the step portion with the cured layer and the photosensitive resin retained in the step portion is cured in this state, there is almost no step between the cured layers, and a laminated body having a smooth surface is formed. can do.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the stereolithography method according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a view schematically showing a manufacturing process of the optical shaping method according to the present invention. FIG. 2 is a schematic perspective view of the evaluation model manufactured in the manufacturing example. In FIG. 2, reference numeral 21 denotes a surface having an inclination of 10 degrees, reference numeral 22 denotes a surface having an inclination of 20 degrees, reference numeral 23 denotes a surface having an inclination of 30 degrees, and reference numeral 24 denotes a surface having an inclination of 40 degrees. , 25 are surfaces having a slope of 50 degrees, 26 is a surface having a slope of 60 degrees, 27 is a surface having a slope of 70 degrees, 28 is a surface having a slope of 80 degrees, and 29 is a surface having a slope of 80 degrees. Is a surface having an inclination of 90 degrees.
[0012]
In the stereolithography method according to the present invention, first, a step of irradiating the photosensitive resin 1 with light 5 to form an N-th cured layer 7 (hereinafter, referred to as “step (A-1)”) is performed. By lowering the elevator 2, the photosensitive resin 1 having a thickness of one layer wraps around the laminate 10 (or on the base plate 3), draws an Nth layer with light 5, cures the photosensitive resin, and The cured layer 7 of the layer is formed, and the cured layer 7 of the Nth layer and the cured layer 8 of the (N-1) th layer are joined. That is, as shown in FIG. 1A, the photosensitive resin 1 having a thickness of one layer is wrapped around the base plate 3, the N layer is drawn with light 5, and the photosensitive resin 1 is cured.
[0013]
In the present invention, all conventionally known photosensitive resins can be used as the photosensitive resin. As the light for curing the photosensitive resin, an infrared ray, a visible light ray, an ultraviolet ray, an ultraviolet laser, or the like is used depending on the photosensitive resin used.
[0014]
Next, the laminated body 10 is pulled up so that the N-th cured layer 7 comes out above the surface of the photosensitive resin, whereby the N-th cured layer 7 and the (N-1) -th cured layer 8 are formed. (Hereinafter, referred to as “step (B-1)”). Subsequently, a step of curing the photosensitive resin liquid 4 staying at the step portion while the N-th cured layer 7 is on the photosensitive resin liquid surface (hereinafter referred to as “step (C-1)”). Do. That is, as shown in FIG. 1B, for example, the base plate 3 is raised, and the N-th cured layer is irradiated with light 5 according to the shape of the (N-1) -th cured layer 8.
[0015]
When the laminate 10 is pulled up so that the N-th cured layer 7 comes out above the liquid surface of the photosensitive resin, the peripheral portion of the N-th cured layer 7 and the (N-1) -th cured layer 8 The photosensitive resin liquid stays at the steps, and fills the steps to form a slope. When the staying photosensitive resin liquid 4 staying at the step portion is cured, a laminate having almost no step is obtained.
[0016]
The width of raising the laminate 10 is the thickness of the cured layer in FIG. 1B, but in the present invention, the width of lifting the laminate 10 is not particularly limited as long as it is equal to or greater than the thickness of the cured layer. It is preferable that the width of pulling up the laminate 10 is equal to or more than two layers of the thickness of the cured layer, because unnecessary photosensitive resin flows down.
[0017]
Next, a step of pulling the stacked body 10 down to the position where the (N + 1) th layer is formed (hereinafter referred to as “step (D-1)”) is performed. By lowering the laminate 10 to the position where the (N + 1) layer is formed, the photosensitive resin 1 having a thickness of one layer wraps around the N-th laminate 7. That is, as shown in FIG. 1C, the base plate 3 is lowered to a depth at which the next (N + 1) layer is formed.
[0018]
Subsequently, as shown in FIG. 1D, the (N + 1) layer is drawn to cure the photosensitive resin, and is also joined to the lower cured layer.
When the laminate 10 is pulled down to the position where the (N + 1) th layer is formed, the laminate 10 is once pulled down below the position where the (N + 1) th layer is formed, and then the laminate 10 is moved down to the position where the (N + 1) th layer is formed. It may be raised to the position where it is formed.
[0019]
When the (N + 1) -th layer is drawn with light 5, the photosensitive resin 1 is cured to form the (N + 1) -th cured layer 9 and the N-th cured layer 7 and the (N + 1) -th cured layer 9 And join.
[0020]
By repeating the steps (A-1), (B-1), (C-1) and (D-1) up to the final layer of the shape, a three-dimensional model can be formed.
When irradiating light, it is desirable to keep the remaining photosensitive resin liquid from moving.
[0021]
In the stereolithography method of the present invention, after the N-th cured layer is formed, the N-th cured layer is raised, and the uncured photosensitive resin stays at the periphery of the N-th cured layer. Since the uncured photosensitive resin is cured, a laminate having almost no steps can be formed.
[0022]
As described above, the stereolithography method according to the present invention has been described, but the present invention is not limited to the above-described example, and can be variously modified within the technical idea of the present invention.
For example, it can be performed as follows.
[0023]
First, a step of forming an N-th cured layer (hereinafter referred to as “step (A-2)”) is performed in the same manner as in the step (A-1).
Next, in the same manner as in the step (B-1), the laminate is pulled up so that the N-th cured layer comes out above the surface of the photosensitive resin liquid. 1) A step (hereinafter, referred to as “step (B-2)”) of retaining the photosensitive resin liquid in a step portion with respect to the cured layer of the layer is performed.
[0024]
Subsequently, in a state where the N-th cured layer is exposed on the surface of the photosensitive resin liquid, light is irradiated only on the photosensitive resin remaining on the step to cure the photosensitive resin liquid remaining on the step. Step (hereinafter, referred to as “Step (C-2)”) is performed.
[0025]
Next, similarly to the step (D-1), a step of lowering the laminate to a position where the (N + 1) th layer is formed (hereinafter, referred to as "step (D-2)") is performed.
A three-dimensional model can be formed by repeating the steps (A-2), (B-2), (C-2) and (D-2) until the final layer of the shape.
[0026]
Even by such a method, after the N-th cured layer is formed, the N-th cured layer is raised, and the uncured photosensitive resin stays at the periphery of the N-th cured layer, Since the uncured photosensitive resin is cured, the same function and effect as described above can be obtained.
[0027]
The stereolithography method of the present invention can be further modified. For example, it can be performed as follows.
First, a step of irradiating the photosensitive resin with light to form at least a part of the N-th layer (hereinafter, referred to as “step (A-3)”) is performed. By lowering the elevator, one layer of photosensitive resin is wrapped around the laminate (or on the base plate), at least part of the Nth layer is drawn with light, and the photosensitive resin is cured to cure the N layer. Form at least part of the eye. Here, only the peripheral portion of the Nth layer is cured, the entire surface of the light irradiation pattern of the Nth layer is cured into a plurality of continuous or discontinuous linear shapes, or the entire surface of the light irradiation pattern of the Nth layer is arbitrarily selected. Is cured into a plurality of dots having the following intervals.
[0028]
Next, in the same manner as in the step (B-1), the laminate is pulled up so that the N-th cured layer comes out above the surface of the photosensitive resin liquid. 1) A step (hereinafter referred to as “step (B-3)”) of retaining the photosensitive resin liquid in a step portion between the cured layer and the layer is performed. When the laminate is pulled up so that the N-th cured layer is above the photosensitive resin liquid surface, the photosensitive resin liquid is formed on the step between the N-th cured layer and the (N-1) th cured layer. Stays and fills the step to form a slope.
[0029]
Subsequently, in a state where the N-th cured layer is exposed on the surface of the photosensitive resin liquid, light is irradiated according to the shape of the (N-1) -th cured layer, and the photosensitive resin remaining at the step portion is irradiated. And a step of curing the N-th layer uncured photosensitive resin (hereinafter referred to as “step (C-3)”). When light is irradiated along the shape of the (N-1) -th cured layer while the N-th cured layer is on the surface of the photosensitive resin liquid, the photosensitive resin remaining at the step is cured. A laminated body having a small number of steps is formed, and the N-th uncured photosensitive resin is cured to form an N-th cured layer.
[0030]
Next, similarly to the step (D-2), a step of lowering the laminate to a position where the (N + 1) th layer is formed (hereinafter, referred to as “step (D-3)”) is performed.
By repeating the steps (A-3), (B-3), (C-3) and (D-3) until the final layer of the shape, a three-dimensional model can be formed.
[0031]
Even by such a method, after the N-th cured layer is formed, the N-th cured layer is raised, and the uncured photosensitive resin stays at the periphery of the N-th cured layer, Since the uncured photosensitive resin is cured, the same function and effect as described above can be obtained.
[0032]
【Example】
Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.
[0033]
Embodiment 1
According to the method of the present invention described above, an evaluation model having an inclined surface every 10 degrees in a range of 10 to 90 degrees with respect to a horizontal plane as shown in FIG. 2 was formed under the following conditions.
[0034]
That is, after the surface of a photosensitive resin liquid (manufactured by Nippon Synthetic Rubber Co., Ltd., SCR200) is irradiated with an ultraviolet laser beam to form an N-th cured layer, the N-th cured layer is coated with the photosensitive resin liquid. Pulling up the laminate by an elevator so that it rises above the surface (corresponding to steps (B-1), (B-2), and (B-3) in the present invention; (Applicable), the photosensitive resin liquid was retained at the step between the N-th cured layer and the (N-1) -th cured layer. After holding for a certain period of time (in Table 1, the amount of standing time of the lifting amount), an ultraviolet laser beam is irradiated according to the shape of the (N-1) th layer of the cured layer to cure the photosensitive resin liquid retained in the step portion. Was. Next, the laminate is lowered by an elevator and held for a certain period of time to allow the photosensitive resin to flow around the upper surface of the N-th cured layer. Then, the laminate is pulled up to a position where the (N + 1) th layer is formed and held for a certain period of time. Then, an ultraviolet laser beam was irradiated to form an (N + 1) th cured layer. An evaluation model was formed by repeating the above steps. After the modeling, the evaluation model was irradiated with a mercury lamp and post-cured for 2 hours.
[0035]
[Table 1]

[0036]
The average surface roughness of each inclined surface of the evaluation model formed as described above was measured using a surface roughness meter (Surfcom 300B, manufactured by Mitutoyo Corporation).
[0037]
[Comparative Example 1]
According to a conventional method, an evaluation model as shown in FIG. 2 was formed under the following conditions.
That is, the surface of a photosensitive resin liquid (SCR200, manufactured by Nippon Synthetic Rubber Co., Ltd.) was irradiated with an ultraviolet laser beam to form an N-th cured layer. Next, the laminate is lowered by an elevator, and held for a certain time to allow the photosensitive resin to flow around the upper surface of the N-th cured layer, and then the stack is pulled up to a position where the (N + 1) -th layer is formed and held for a certain time Then, an ultraviolet laser beam was irradiated to form a (N + 1) th cured layer. An evaluation model was formed by repeating the above steps.
[0038]
[Table 2]

[0039]
The average surface roughness of each inclined surface of the evaluation model formed as described above was measured in the same manner as in Example 1.
[0040]
The above results are shown in FIG. As shown in FIG. 3, according to the method of the present invention, the surface roughness is smaller than that of the conventional method, and the average surface roughness is 15 μm or less.
[0041]
Embodiment 2
An evaluation model was formed in the same manner as in Example 1 except that the layer thickness was set to 300 μm. The average surface roughness of each inclined surface of the obtained evaluation model was measured in the same manner as in Example 1.
[0042]
[Comparative Example 2]
An evaluation model was formed in the same manner as in Comparative Example 1 except that the thickness of the laminate was set to 300 μm. The average surface roughness of each inclined surface of the obtained evaluation model was measured in the same manner as in Example 1.
[0043]
The results are shown in FIG. FIG. 5 shows cross-sectional curves of the inclined surface (broken line) of the evaluation model formed in Example 2 and the inclined surface (solid line) of the evaluation model molded in Comparative Example 2. As shown in FIG. 4, according to the method of the present invention, the surface roughness is smaller than that of the conventional method, and in particular, the average surface roughness is 15 μm or less in all cases on an inclined surface of 30 ° or less. In addition, as shown in FIG. 5, according to the method of the present invention, especially when the inclination angle is small, the step is small and the surface roughness is small.
[0044]
【The invention's effect】
According to the stereolithography method of the present invention, a laminate having a small surface roughness can be formed as compared with the conventional stereolithography method, and a laminate having a small surface roughness can be formed even when the lamination thickness is increased. it can. Therefore, it is not necessary to perform secondary processing such as removing a step of the laminate, and a model having a desired shape can be obtained at low cost and in a short time.
[Brief description of the drawings]
FIG. 1 is a view schematically showing a manufacturing process of an optical shaping method according to the present invention.
FIG. 2 is a schematic perspective view of an evaluation model manufactured in an example.
FIG. 3 is a diagram showing the surface roughness of a slope of an evaluation model formed in Example 1 and an evaluation model formed in Comparative Example 1.
FIG. 4 is a view showing the surface roughness of a slope of an evaluation model formed in Example 2 and an evaluation model formed in Comparative Example 2.
FIG. 5 is a comparison diagram of cross-sectional curves of an evaluation model formed in Example 2 and an evaluation model formed in Comparative Example 2. In the figure, the broken line is a cross-sectional curve of the evaluation model formed in Example 2, and the solid line is a cross-sectional curve of the evaluation model formed in Comparative Example 2.
[Explanation of symbols]
10 laminated body 1 photosensitive resin liquid 2 elevator 3 base plate 4 staying photosensitive resin liquid 5 light

Claims

In the optical molding method of irradiating light to the surface of the photosensitive resin liquid to form a cured layer, and forming a laminated body having a desired three-dimensional shape by laminating a plurality of the cured layers,
(A) irradiating the photosensitive resin with light to form at least a part of an N-th cured layer;
(B) a step of pulling up the laminate so that the N-th cured layer is above the photosensitive resin liquid surface ;
(C) The photosensitive resin liquid remaining in the step portion between the N-th cured layer and the (N-1) -th cured layer in a state where the N-th cured layer is on the photosensitive resin liquid surface is removed. Curing process,
A stereolithography method, comprising:

In the step (A), the step of forming at least a portion of the cured layer of the Nth layer may be performed by curing only the peripheral portion of the Nth layer, or forming the entire surface of the light irradiation pattern of the Nth layer into a plurality of continuous or non-continuous areas. 2. The method according to claim 1, wherein the light irradiation pattern is cured in a continuous linear shape or the entire surface of the N-th light irradiation pattern is cured in a plurality of dots having an arbitrary interval. 3. Stereolithography method.

The stereolithography method according to claim 1, wherein, in the step (B), a width of pulling up the laminate is equal to or more than two thicknesses of the cured layer.

4. The method according to claim 1, wherein in the step (C), light is irradiated according to the shape of the cured layer of the (N−1) th layer to cure the photosensitive resin remaining in the step portion. 5. The stereolithography method according to claim 1.